• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.187-188
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• 2002

Rubber has large differences in elastic characteristics from the other solid materials such as metals. Firstly, the rubber exhibits considerably large elastic compliance. Second is highly non-linear elasticity in which the compliance decreases with increase in strain. The main objective in this research is to reveal the dependence of rubber friction upon these elastic characteristics of the rubber in detail. A super elastic FEM analysis is carried out with using an elastic property of practical rubber. From the calculated result, it is cleared that the rubber makes large real contacting area easier than the metals.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.08a
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• pp.173-173
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• 2010

$Bi_4Ti_3O_{12}$ ($B_4T_3$) is a unique ferroelectric material that has a relatively high dielectric constant, high Curie temperature, high breakdown strength, and large spontaneous polarization. As a result this material has been widely studied for many applications, including nonvolatile ferroelectric random memories, microelectronic mechanical systems, and nonlinear-optical devices. Several reports have appeared on the use of Mn dopants to improve the electrical properties of $B_4T_3$ thin films. Mn ions have frequently been used for this purpose in thin films and multilayer capacitors in situations where intrinsic oxygen vacancies are the major defects. However, no systematic study of the optical properties of $B_4T_3$ films has appeared to date. Here, we report optical data for these films, determined by spectroscopic ellipsometry (SE). We also report the effects of thermal annealing and Mn doping on the optical properties. The SE data were analyzed using a multilayer model that is consistent with the original sample structure, specifically surface roughness/$B_4T_3$ film/Pt/Ti/$SiO_2$/c-Si). The data are well described by the Tauc-Lorentz dispersion function, which can therefore be used to model the optical properties of these materials. Parameters for reconstructing the dielectric functions of these films are also reported. The SE data show that thermal annealing crystallizes $B_4T_3$ films, as confirmed by the appearance of $B_4T_3$ peaks in X-ray diffraction patterns. The bandgap of $B_4T_3$ red-shifts with increasing Mn concentration. We interpret this as evidence of the existence deep levels generated by the Mn transition-metal d states. These results will be useful in a number of contexts, including more detailed studies of the optical properties of these materials for engineering high-speed devices.

• Kyungpook Mathematical Journal
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• v.45 no.2
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• pp.177-189
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• 2005

We obtain characterizations of T-fuzzy (implicative) filters and some properties of T-product of fuzzy (implicative) filters in lattice implication algebras. We also establish the extension property for T-fuzzy implicative filters.

• Journal of applied mathematics & informatics
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• v.28 no.1_2
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• pp.499-507
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• 2010

In this note, we study the local spectral properties of semi-shifts. If $T\;{\in}\;L(X)$ is a semi-shift on a complex Banach space X, then T is admissible. We also prove that if $T\;{\in}\;L(X)$ is subadmissible, then $X_T(F)\;=\;E_T(F)$ for all closed $F\;{\subseteq}\;\mathbb{C}$. In particular, every subscalar operator on a Banach space is admissible.

• Bulletin of the Korean Mathematical Society
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• v.54 no.4
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• pp.1095-1110
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• 2017

The t-wise intersection is a useful property of a linear code due to its many applications. Recently, the second author determined the t-wise intersection of a relative two-weight code. By using this result and generalizing the finite projective geometry method, we will present the t-wise intersection of a relative three-weight code and its applications in this paper.

• Honam Mathematical Journal
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• v.34 no.2
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• pp.289-295
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• 2012

In this note we prove the space (A, ${\parallel}.{\parallel}$) is a Banach space and ${\parallel}ab{\parallel}{\leq}{\parallel}a{\parallel}{\parallel}b{\parallel}$ for $a,b{\in}A$ where $A:=\{a:=(a_t)_{t{\in}G}:{\sum}_{t{\in}G}{\parallel}a_t{\parallel}_t<{\infty}\}$, $G=\mathbb{N}^*$. Also we show some property in (A, ${\parallel}.{\parallel}$).

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.26 no.2
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• pp.108-120
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• 2022

We considered qualitative behaviour of the generalization of Einstein's model of Brownian motion when the key parameter of the time interval of free jump degenerates. Fluids will be characterised by number of particles per unit volume (density of fluid) at point of observation. Degeneration of the phenomenon manifests in two scenarios: a) flow of the fluid, which is highly dispersing like a non-dense gas and b) flow of fluid far away from the source of flow, when the velocity of the flow is incomparably smaller than the gradient of the density. First, we will show that both types of flows can be modeled using the Einstein paradigm. We will investigate the question: What features will particle flow exhibit if the time interval of the free jump is inverse proportional to the density and its gradient ? We will show that in this scenario, the flow exhibits localization property, namely: if at some moment of time t₀ in the region, the gradient of the density or density itself is equal to zero, then for some T during time interval [t₀, t₀ + T] there is no flow in the region. This directly links to Barenblatt's finite speed of propagation property for the degenerate equation. The method of the proof is very different from Barenblatt's method and based on the application of Ladyzhenskaya - De Giorgi iterative scheme and Vespri - Tedeev technique. From PDE point of view it assumed that solution exists in appropriate Sobolev type of space.

• Journal of KIISE
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• v.44 no.9
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• pp.966-975
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• 2017

In Internet of Things (IoT), the aim of the nodes (called 'Things') is to exchange information with each other, whereby they gather and share information with each other through self decision-making. Therefore, we cannot apply existing aggregation algorithms of Wireless sensor networks that aim to transmit information to only a sink node or a central server, directly to the IoT environment. In addition, since existing algorithms aggregate information from all sensor nodes, problems can arise including an increasing number of transmissions and increasing transmission delay and energy consumption. In this paper, we propose the clustering and property based data exchange method for energy efficient information sharing. First, the proposed method assigns the properties of each node, including the sensing data and unique resource. The property determines whether the node can respond to the query requested from the other node. Second, a cluster network is constructed considering the location and energy consumption. Finally, the nodes communicate with each other efficiently using the properties. For the performance evaluation, TOSSIM was used to measure the network lifetime and average energy consumption.

• Korean Journal of Human Ecology
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• v.15 no.5
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• pp.783-790
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• 2006

The purposes of this study are to analyze shopmasters' knowledge of apparel merchandise and textile recognition and to investigate the effects of demographic variables on them. Shopmasters' knowledge of apparel merchandise was analyzed on a factor basis. Four factors of apparel merchandise were fashion property, material property, function property and management property. The textile knowledge level of shopmasters was 72.44%. Considering each part of textile knowledge, basic property was 74.69%, comfort 72.17%, management 68.36% and finishing 77.33%. The level of recognition in finishing area was the highest and the level of recognition in management area was the lowest. There were significant differences in the textile knowledge by gender and working period. Female's textile knowledge level was higher. The longer the working period is, the higher the level of textile knowledge is. Shopmasters recognized the finishing area better than university students did. But both of the groups didn't recognize the management area well.

• Journal of Internet of Things and Convergence
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• v.9 no.6
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• pp.83-92
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• 2023

The purpose of this study is to provide a rational management strategy to improve the management performance of companies through intellectual property activities. Through this study, we aim to explore countermeasures to strengthen competitiveness in a changing global environment. A survey of 200 companies was conducted from September 1 to October 30, 2023. Statistical analysis was conducted using frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, multiple regression analysis, and difference analysis. The conclusions are as follows. First, the impact of intellectual property activities on management performance was found to be creation and utilization. Second, the impact of management strategies on management performance was found to be differentiation strategy, cost advantage strategy, and concentration strategy. Third, cost advantage strategy has a partial mediation effect on the relationship between creation activities and managerial performance of intellectual property activities. Fourth, the differentiation strategy has a partial mediating effect on the relationship between the creation of intellectual property activities and managerial performance. In addition, differentiation strategy has a full mediating effect on the relationship between the utilization of intellectual property activities and performance. Fifth, concentration strategy has a partial mediating effect on the relationship between intellectual property activity utilization and management performance. Sixth, there is a difference between creation activities, protection activities, utilization activities, cost advantage strategy, differentiation strategy, financial performance, and non-financial performance based on venture certification status. As the importance of intellectual property is increasing in the era of technological hegemony, IoT companies will need to improve their management performance through venture certification and strategies utilizing intellectual property in order to secure future competitiveness. Based on this study, we hope that IoT companies will maximize their performance by implementing efficient strategies that consider IP activities.